Re: [PATCH v4 1/3] ARM: dts: aspeed: ast2600evb: Add sdhci node and gpio regulator for A2 evb.

Steven Lee
2021-05-24T02:36:19Z

The 05/21/2021 09:25, Joel Stanley wrote:
> Hi Steven,
>
> On Thu, 20 May 2021 at 10:16, Steven Lee <steven_lee@aspeedtech.com> wrote:
> >
> > AST2600 A2(or newer) EVB has gpio regulators for toggling signal voltage
> > between 3.3v and 1.8v, the patch adds sdhci node and gpio regulator in the
> > new dts file and adds commment for describing the reference design.
>
> spelling: comment
>

Thanks, will correct the typo.

> I need you to justify the separate dts for the A2 EVB.
>
> What would happen if this device tree was loaded on to an A1 or A0?
>

Since the clock default value(SCU210) of A1 and A0 are different to A2,
the following error would happen if A2 device tree was loaded on A1/A0.

```
[ 133.179825] mmc1: Reset 0x4 never completed.
[ 133.184599] mmc1: sdhci: ============ SDHCI REGISTER DUMP ===========
[ 133.191786] mmc1: sdhci: Sys addr: 0x00000000 | Version: 0x00000002
[ 133.198972] mmc1: sdhci: Blk size: 0x00007008 | Blk cnt: 0x00000001
[ 133.206158] mmc1: sdhci: Argument: 0x00000c00 | Trn mode: 0x00000013
[ 133.213343] mmc1: sdhci: Present: 0x01f70001 | Host ctl: 0x00000011
[ 133.220528] mmc1: sdhci: Power: 0x0000000f | Blk gap: 0x00000000
[ 133.227713] mmc1: sdhci: Wake-up: 0x00000000 | Clock: 0x00008007
[ 133.234898] mmc1: sdhci: Timeout: 0x0000000b | Int stat: 0x00000000
[ 133.242083] mmc1: sdhci: Int enab: 0x00ff0083 | Sig enab: 0x00ff0083
[ 133.249268] mmc1: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000
[ 133.256453] mmc1: sdhci: Caps: 0x07f80080 | Caps_1: 0x00000007
[ 133.263638] mmc1: sdhci: Cmd: 0x0000341a | Max curr: 0x001f0f08
[ 133.270824] mmc1: sdhci: Resp[0]: 0x00000000 | Resp[1]: 0x01dd7f7f
[ 133.278009] mmc1: sdhci: Resp[2]: 0x325b5900 | Resp[3]: 0x00400e00
[ 133.285193] mmc1: sdhci: Host ctl2: 0x00000000
[ 133.290148] mmc1: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0xbe041200
[ 133.297332] mmc1: sdhci: ============================================

```

Besides, A1/A0 EVBs don't have regulator, vmmc and vqmmc should be
removed from sdhci node of A1/A0 dts.

> Would this device tree be used for the A3 (and any future revision?)
>

Yes, A3 can use the A2 dts.

> An alternative proposal: we modify the ast2600-evb.dts to support the
> A2 (which I assume would also support the A3).
>
> If we need a separate board file for the A0 and A1 EVB, we add a new
> one that supports these earlier revisions. Or we decide to only
> support the latest revision in mainline.
>

In this patch, I add a new dts to support A2 sdhci, and include the
original dts since the other settings can be loaded on A2.
Do you mean creating a new file(e.g. aspeed-ast2600-evb-a1.dts) for A1,
and modifying the original aspeed-ast2600-evb.dts for supporting A2?

If we decide to only support the latest version in mainline, users
should mark vmmc and vqmmc as comment and modify clk-phase manually
for supporting A1.

> >
> > Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
> > ---
> > arch/arm/boot/dts/aspeed-ast2600-evb-a2.dts | 98 +++++++++++++++++++++
> > 1 file changed, 98 insertions(+)
> > create mode 100644 arch/arm/boot/dts/aspeed-ast2600-evb-a2.dts
> >
> > diff --git a/arch/arm/boot/dts/aspeed-ast2600-evb-a2.dts b/arch/arm/boot/dts/aspeed-ast2600-evb-a2.dts
> > new file mode 100644
> > index 000000000000..d581e8069a82
> > --- /dev/null
> > +++ b/arch/arm/boot/dts/aspeed-ast2600-evb-a2.dts
> > @@ -0,0 +1,98 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +// Copyright 2021 IBM Corp.
> > +
> > +#include "aspeed-ast2600-evb.dts"
> > +#include <dt-bindings/gpio/gpio.h>
> > +
> > +/ {
> > + model = "AST2600 A2 EVB";
> > + compatible = "aspeed,ast2600";
>
> Will this override the "aspeed,ast2600-evb" compatible in the dts? I
> think you can drop the compatible string here and just use the one
> from the DTS.
>

Thanks for review, I will remove it.

> > +
> > + vcc_sdhci0: regulator-vcc-sdhci0 {
> > + compatible = "regulator-fixed";
> > + regulator-name = "SDHCI0 Vcc";
> > + regulator-min-microvolt = <3300000>;
> > + regulator-max-microvolt = <3300000>;
> > + gpios = <&gpio0 168
>
> We have macros for describing the GPIOs:
>
> ASPEED_GPIO(V, 0)
>
> > + GPIO_ACTIVE_HIGH>;
>
> This can go on one line.
>
> > + enable-active-high;
> > + };
> > +
> > + vccq_sdhci0: regulator-vccq-sdhci0 {
> > + compatible = "regulator-gpio";
> > + regulator-name = "SDHCI0 VccQ";
> > + regulator-min-microvolt = <1800000>;
> > + regulator-max-microvolt = <3300000>;
> > + gpios = <&gpio0 169
> > + GPIO_ACTIVE_HIGH>;
> > + gpios-states = <1>;
> > + states = <3300000 1>,
> > + <1800000 0>;
> > + };
> > +
> > + vcc_sdhci1: regulator-vcc-sdhci1 {
> > + compatible = "regulator-fixed";
> > + regulator-name = "SDHCI1 Vcc";
> > + regulator-min-microvolt = <3300000>;
> > + regulator-max-microvolt = <3300000>;
> > + gpios = <&gpio0 170
> > + GPIO_ACTIVE_HIGH>;
> > + enable-active-high;
> > + };
> > +
> > + vccq_sdhci1: regulator-vccq-sdhci1 {
> > + compatible = "regulator-gpio";
> > + regulator-name = "SDHCI1 VccQ";
> > + regulator-min-microvolt = <1800000>;
> > + regulator-max-microvolt = <3300000>;
> > + gpios = <&gpio0 171
> > + GPIO_ACTIVE_HIGH>;
> > + gpios-states = <1>;
> > + states = <3300000 1>,
> > + <1800000 0>;
> > + };
> > +};
> > +
> > +&sdc {
> > + status = "okay";
> > +};
> > +
> > +/*
> > + * The signal voltage of sdhci0 and sdhci1 on AST2600-A2 EVB is able to be
> > + * toggled by GPIO pins.
> > + * In the reference design, GPIOV0 of AST2600-A2 EVB is connected to the
> > + * power load switch that providing 3.3v to sdhci0 vdd, GPIOV1 is connected to
> > + * a 1.8v and a 3.3v power load switch that providing signal voltage to
>
> nit: provides
>

Will modify it.

> > + * sdhci0 bus.
> > + * If GPIOV0 is active high, sdhci0 is enabled, otherwise, sdhci0 is disabled.
> > + * If GPIOV1 is active high, 3.3v power load switch is enabled, sdhci0 signal
> > + * voltage is 3.3v, otherwise, 1.8v power load switch will be enabled,
> > + * sdhci0 signal voltage becomes 1.8v.
> > + * AST2600-A2 EVB also support toggling signal voltage for sdhci1.
>
> nit: supports
>

Will modify it.

> > + * The design is the same as sdhci0, it uses GPIOV2 as power-gpio and GPIOV3
> > + * as power-switch-gpio.
> > + */
> > +&sdhci0 {
> > + status = "okay";
> > + bus-width = <4>;
> > + max-frequency = <100000000>;
> > + sdhci-drive-type = /bits/ 8 <3>;
> > + sdhci-caps-mask = <0x7 0x0>;
> > + sdhci,wp-inverted;
> > + vmmc-supply = <&vcc_sdhci0>;
> > + vqmmc-supply = <&vccq_sdhci0>;
> > + clk-phase-sd-hs = <7>, <200>;
> > +};
> > +
> > +&sdhci1 {
> > + status = "okay";
> > + bus-width = <4>;
> > + max-frequency = <100000000>;
> > + sdhci-drive-type = /bits/ 8 <3>;
> > + sdhci-caps-mask = <0x7 0x0>;
> > + sdhci,wp-inverted;
> > + vmmc-supply = <&vcc_sdhci1>;
> > + vqmmc-supply = <&vccq_sdhci1>;
> > + clk-phase-sd-hs = <7>, <200>;
> > +};
> > +
> > --
> > 2.17.1
> >